Participating instruments and points-of-contact (POCs):

Scientific Objectives and Justification:

We propose to study the sources of fast and slow solar wind by
investigating how the flux tubes change from a high-speed to a low-speed
region. We will select a polar hole with a clearly-defined streamer region
nearby and study both regions and the boundary between the polar coronal
hole and the surrounding quiet Sun region from the limb to SOHO/UVCS
heights. We aim to measure how the plasma physical properties change
between the two wind regions, and with height, and how the flux tubes
expand with heliocentric distance. In particular, this campaign will study
the evolution of the transition from fast to slow wind source regions as a
function of time and heliocentric distance from the limb and will provide
important experimental constraints to theoretical models.

centering the field of view on the boundary between the coronal
hole and the quiet Sun

using a much larger set of spectral lines

extending the study to 2-4 solar radii above the limb.

Operational Considerations

The target will be selected by M. P. Miralles, at least, 3 days prior to
the start of the UVCS observation and will be communicated to the other
instruments involved. E. Landi will be in Japan and will coordinate EIS and
SUMER sequences.

SOHO/UVCS will run this campaign from Nov 6 to 17, 2007. We will run a
joint SUMER/EIS/UVCS observation coincidental with this time period.

Detailed Observing Sequences:

SOHO/SUMER and Hinode/EIS will observe the same field of view at several
positions outside the solar limb up to the maximum distance allowed by
their pointing systems. Hinode/EIS observations will consist of several
repetitions of a single sequence: a 25-step raster with the 2" slit that
will observe the entire EIS wavelength range downloading the central 400"
of the EIS slit. The exposure time is 150 s and this study (which lasts
about 1 hour and has a data rate of ~53kbit/s) will be repeated at a few
locations at different heliocentric distances from the solar limb. We
expect to run it 7 times for a total of around 7 hours. The SOHO/SUMER
sequence will also take around 7 hours to complete.

The SOHO/UVCS sequence will last longer. The center of the UVCS slit will
be at the same position angle of the EIS and SUMER observations lower down.
SOHO/UVCS will observe a set of temperature and outflow diagnostic lines
(including O VI and H I Lyman alpha) with a range of exposure times at
higher heights.

We are planning to repeat the Hinode/EIS and SOHO/SUMER sequences at least
twice during the campaign between Nov 6 and Nov 17, 2007.